How to write Unobtrusive Ajax calls in jquery with rails

I am currently in rails 3.1. I wanna achieve ajax call in jquery with out the use of form_for method.

My current page is localhost:3000/posts/show/2 and I have a button in the page and it does not belong under any form. On click of that button, I have to send an ajax call to the create action in the Comments controller and this is the jquery code

    $(function(){
        $('#add_button').click(function(){
            $.post('comments/create', function(data) {
              $('.res开发者_运维百科ult').html(data);
            });
            return false;
        });
    });

but this didnt end in an ajax call but it was a browser call and got an error saying could not find the method in Posts controller. I even tried changing the url in $.post to Comments.create (fyi, I have added necessary changes in routes.rb) but still i end up getting a browser call and an error.

How can i restrict it to pure ajax call and how to access the correct url(i.e. to access action of a comments controller inside the view of a Posts controller)?

---

If you want to do it 'the rails way' I would suggest you read this excellent post: http://www.alfajango.com/blog/rails-3-remote-links-and-forms/

That way you'll be able to bind your code to rail's remote link code.